Gunsight drive linkage



1966 c. R. SANDAHL. 3,263,567

GUNS IGHT DRIVE LINKAGE Filed March 15, 1957 2 Sheets-Sheet 1 IN V ENTOR.

BY Earl R- Sandal-ll Aug. 2, 1966 g, SANDAHL 3,263,557

GUNSIGHT DRIVE LINKAGE Filed March 15, 1957 a Sheets-Sheet 2 42 8INVENTOR.

[I at]. R. Sandal-L1 WLQ W -fjW swem gvw Patented August 2, 19663,263,567 P GUNSIGHT DRIVE LINKAGE Carl R. Sandahl, Oakland, N.J.,assignor to the United States of America as represented by the Secretaryof the Army Filed Mar. 15, 1957, Ser. No. 646,505 4 Claims. (Cl. 89- 41)The invention relates to gunsight drive linkages, and more particularlyto gunsight linkages wherein the sight may be adjustably positionedrelative to the gun.

In the gunsight art, many various means have been utilized in linkingthe sight to the gun such that the line of sight will remain parallel tothe gun at all times irrespective of the guns traversing and elevationalmovements. Most of the present gunsight linkages are heavy and bulky andunsuitable for use with guns mounted on vehicles or other installationswherein space limitations are restricted. Also, it has heretofore beendifiicult to obtain a linkage which would permit the gun to beeffectively used against anti-aircraft targets as well as terrestrialtargets.

It is thus an object of the invention to design a gun sight linkagewhich is capable of operating a gunsight effectively for use againstboth air and terrestrial targets.

A further object of the invention is to produce an accurate gunsightlinkage which is compact, lightweight, and may be readily adjusted tothe gunners height.

Another object of the invent-ion is to design a gunsight drive linkagewhich will maintain the line of sight parallel to the gun at all timesand will also operate a protective shield when used against terrestrialtargets.

These and other objects of the invention will become apparent whenviewed in relation to the eccompanying specification and drawingswherein:

FIGURE 1 is a perspective view of the invention as used in an armoredvehicle.

FIGURE 2 is a cross-sectional elevational view of the invention takenalong the line II-II of FIGURE 1.

FIGURE 3 is a cross-section elevational view of the invention takenalong the line IIIIII of FIGURE 1.

Although the invention may be used with any type of sight aimed gun,FIGURE 1 illustrates use with a battery of machine guns mounted in avehicle.

As seen in FIGURE 1, a turret 10 which is mounted on a vehicle, notshown, provides the housing for the guns and gunner. The turret 10 isprovided with a hatch 12, which may be folded back for purposes laterdescribed. A series of machine guns 14 are mounted for elevationalmovement within turret 10, which in turn is rotatably supported in thevehicle, thus enabling the guns 14 to be aimed in any direction. Theturret and guns are preferably power driven, however, the gunsightlinkage may be operated by either manual or power driven guns. Theelevation of gun 14 will be obtained by rotatable means including a gearsector and gun trunnions through a torque exerted by the gear section 16which is connected to and has the same center of rot-ation as the guntrunnions and is rotated by power means engaging with the teeth on theperiphery thereof.

Elevation gear sectors or the equivalents are present on all mountedguns, and thus it will be observed the following described gunsightlinkage may be adapted to any type of mounted gun. In the disclosedembodiment where guns are mounted on both sides of the gunner, thelinkage is duplicated to provide accurate operation and equal operationforces and in the description of the invention like reference numbersindicate similar components.

The gunsight linkage consists of a pair of arms 18, one end of which ispivotally connected to the rotatable means for example to the gearsector 16 and the other ends are pivotally attached to pivot plate 20.The ends of arms 18 are pivotally connected to the rotatable means forexample to the gear sector 16 and to pivot plate 20 at pointsdiametrically equal and opposite to each other in respect to the centerof rotation of gun trunnions and gear sector and to the center of pivotplate rotation, thereby constituting a paralellogram system.

As seen in FIGURE 2, the pivot plate 20 is mounted by means ofanti-friction bearing 22 to the shaft 24. A bolt 26 extends throughshaft 24 and is provided with a nut 28 at one end and an operating knob30 at the other. The nut 28 is located inside a box type bracket 32,which is of an arcuate shape (FIGURE 1) and is fixed to the turret bodywhereby the shaft 24 may be adjusted along the bracket and held in aselected position by turning knob 30 causing nut 28 to draw the shaft 24into engagement with the bracket 32.

The pivot plate 20 is provided with a tubular extension 34 surroundingshaft 24 on which is keyed a gear 36 which will rotate with plate 20. Apair of anti-friction bearings 38 journal a housing 40 to the extension34, which encompasses the gear 36, as shown in FIGURE 2, thus it will beobserved that pivot plate 20 and housing 40 will rotate about the sameaxis.

A rack 42 is slidably carried by housing 40, within a bearing sleeve 44,and engages the teeth of gear 36, such that if the housing 40 shouldrotate relative to plate 20, the rack 42 will slide within sleeve 44. Alocking pin 46 -is also located within housing 40, and it is positionedso as to engage a hole 48 within plate 20. A spring 49 constantly urgespin 46 in the retracted position, however a bayonet groove 50, withinhousing 40, will co-operate with surfaces 52 of knob 54 to hold the pin46 within hole 48 to prevent relative rotation of housing 40 and pivotplate 20, when desired.

A rod 56 is rigidly aflixed to housing 40 and extends therefrom, asshown in FIGURE 1, while the rack 42 projects from housing 40 in spacedparallel relation to the rod 56. The rod 56 terminates at the housing 58and is attached rigidly thereto while the rack 42 projects into theinterior of the housing 58 as seen in. FIGURE 3.

The housing 58 contains a sleeve type bearing 60 for accommodating rack42 (see FIGURE 3) and is also provided with a pair of anti-frictionbearings 62 which rotatably support the shaft 64. A gear 66 is keyed toshaft 64 and engages rack 42 whereby reciprocation of the rack willcause the shaft 64 to rotate.

The outer portion of shaft 64 is reduced in diameter, and a bracket 68is afiixed to the extreme end for rotation therewith. A pivot pin 70 isslidably carried by shaft 64 within bore 72 and is connected to thesliding arm 74 by a pin 76. A knurled sleeve 78 is also connected to arm74 by pin 76 and telescopingly engages the enlarged diameter of shaft64, thus sleeve 78 may be gripped by the gunner and moved to the right,as viewed in FIGURE 3, thereby also moving arm 74 and pin 70 to theright. A slot 80, cut in shaft 64, permits pin 76 to be translatedwithin limits, and the spring 82 will bias the movable elements 70, 74,76 and 78 to the left.

A support shaft 84 is located adjacent the end of shaft 64 and providesthe means for supporting the reduced end thereof. Support shaft 84 isprovided with a bore 86 and is rotatably held in a position byanti-friction bearings 88 and bracket 90, which is an integral part ofthe turret 10. Thus, support shaft 84 will provide a rotatable supportfor the shaft 64 when the pivot pin 70 engages the bore 86.

The gunsight 92, which is of the reflex type, is attached to the bracket68 by a series of screws 94 and will therefore rotate with the shaft 64.

The shield 98 is of an arcuate channel shape and is adapted to receivethe gunsight 92 within the channel.

. V A smallaopening is formed inshield 98 in alignment. with the lens ofgunsight 92, and a large opening is cut in turret 10 such that thegunner may see outside the turret by locking into the gunsight 92 whilethe shield 98 will protect the gunsight from exterior damage. The shield98 is supported by support shaft 84 which is supported by bearing 88mounted in bracket 90. A hole 100 is drilled in shield 98 into which thestud 102, which is carried by arm 74, may project. A bore 104 is drilledin bracket 68 such that stud 102 will extend through bracket 68 beforeengaging with hole 100, thus the shield 96 will also rotate aboutsupport shaft 84 in synchronism with the shaft 64.

The operation of the gunsight linkage is as follows:

When the guns 14 are to be used on terrestrial targets, the hatch 12will be closed, and the linkage will be in the relationship shown by thesolid lines of FIGURE 1. As shown in FIGURE 3, the pin 70 will be withinbore 86 and stud 102 engages hole 100 and the locking pin 46, FIGURE 2,will be biased out of contact with hole 48.

As the gunner sights the target, he will operate the turret rotating andgun elevation means until the sight 92 indicates the guns are aimed atthe target, thus as the guns are elevated or depressed, the sight mustmove to maintain the line of sight parallel to the gun at all times. Itis the function of the linkage system to maintain this parallelrelationship by a parallelogram as will be apparent.

As the guns 14 are elevated or depressed, the gear sector 16 will rotatethrough an equal movement causing the arms 18 to rotate pivot plate 20about the shaft 24. R- tation of plate 20 will likewise rotate gear 36which will cause rack 42 to be axially translated. Translation of rack42 will react on gear 66 rotating the shaft 64. Since gunsight 92 andshield 98 are drivingly connected to the shaft 64 by means of bracket 68and stud 102, respectively, the rotation of the guns 14 will thus betransmitted to the gunsight 92.

The parallelism between the gunsight and guns is assured by the factthat the gear sector 16, arms 18 of equal length and pivot plate 20constitute a parallelogram linkage system while the gears 36 and 66 havethe same gear ratios so that rotation of gear 36 on rotation of pivotplate 20 causes identical rotation of gear 66 through rack 42. Sincegear 66 drives shaft 64 to which the gunsight 92 is connected the lineof sight through the gunsight and guns will always be parallel to allelevations of the guns 14.

To use the guns 14 against air targets, the hatch 12 must first heopened to the position shown in FIGURE 1, after hatch 12 is opened theoperator will grasp the sleeves 78 and move them in a direction awayfrom the gunsight 92. This motion will cause the pin 76, pivot pin 70and arm 74 to also move in the direction of sleeve 78 withdrawing pin 70from bore 86 and removing stud 102 from the hole 100. While the pin 70and stud 102 are held in the retracted position, the gunsight 92 may belifted upwardly out of the turret to a location as shown by the dottedlines of FIGURE 1. When the gunsight 92 is raised thusly, the shield 98remains in the turret 10 pivotally mounted on the support shaft 84.

The gunsight 92 is raised until the locking pin 46 aligns with hole 48,pin 46 is then inserted in hole 48 and held therein by means of bayonetjoint 50-52, thus the gunsight will be locked in the elevated position.As the gunsight 92 is raised housing 40 rotates relative to plate 20 sothat the line of sight will remain parallel to the guns due to theaction of rack 42 and gears 36 and 66. However, once pin 46 engages hole48, this action of rack 42 and gears 36 and 66 will be renderedinoperative as there will be no relative rotation between plate 20 andhousing 40. Therefore, when the guns 14 are being used against aircrafttargets, parallelism between the line of sight and the guns aremaintained by the parallelogram linkage defined by gear sector 16, plate20 and arms 18.

Since gunners of different heights will require differentpositionsof thegunsight 92, adjnstmentmaybemade...

by unloosening nut 28 through knob 30, relocating shaft 24 in thebracket 32 and retightening nut 28.

To return the gunsight 92 to the internal turret position, the pin 46 isretracted, sleeves 78 are moved away from the gunsight and the sight islowered until the pin 70 and stud 102 are inserted into the bore 86 andhole 100, respectively.

It is thus apparent that the invention discloses a gunsight drivelinkage which enables a gunsight to be used for either terrestrial orair targets, will always maintain a parallel relationship between theline of sight and gun, and will drive a protective shield in theterrestrial position while providing a wide variety of sight positions.

It will be understood that various modifications of the disclosedembodiment may be apparent to those skilled in the art without departingfrom the spirit and scope of the invention, and it is intended that theinvention be confined only by the breadth of the following claims.

I claim:

1. A gunsight drive linkage comprising, in combination, rotatable meansincluding a gear sector for elevating a gun about a first center ofrotation, a pivot plate spaced therefrom and adapted to rotate about asecond center of rotation, a pair of arms pivotally connecting at endsthereof said rotatable means and said pivot plate at points spacedradially from the respective said first and second centers of rotationand constituting a parallelogram linkage providing correspondingrotation of said rotatable means and said pivot plate through said arms,a first gear fixed to said pivot plate, a first housing rotatablysupported on said pivot plate, a rack slidably supported in said firsthousing in engagement with said first gear, a second housing held inconnected spaced relation to said first housing by a common connectingmember, a shaft rotatably journaled in said second housing, a secondgear keyed to said shaft within said second housing and in engagementwith said rack, rotation of said shaft thereby being responsive torotation of said second gear which through said rack, first gear andarms is responsive to rotation of said rotatable means, and a gunsightfixed to said shaft and thereby responsive to elevation of the gun. Y

2. A gunsight drive linkage as defined in claim 1 and further comprisinga rotatable support shaft positioned adjacent an end of said shaft, ashield mounted on said support shaft, and means carried by said shaftfor engagement with said support shaft and said shield.

3. A gunsight drive linkage as defined in claim 2, wherein said meanscarried by said shaft comprises an axially movable pin and stud whichco-act with corresponding holes formed in said support shaft and saidshield, respectively.

4. A gunsight drive linkage for a gunsight adapted for selective useagainst terrestrial and air targets comprising, in combination,rotatable means including a gear sector for elevating a gun about afirst center of rotation, a pivot plate spaced therefrom and adapted torotate about a second center of rotation, a pair of arms pivotallyconnecting at ends thereof said rotatable means and afirst housingrotatably supported on said pivot plate,

a rack slidably supported in said first housing in engagement with saidfirst gear, a second housing held in connected spaced relation to saidfirst housing by a common connecting member, a shaft rotatably journaledin said second housing, a second gear keyed to one end of said shaftwithin said second housing and in engagement with said rack, rotation ofsaid shaft thereby being responsive to rotation of said second gearwhich through said rack, first gear and arms is responsive to rotationof said rotatable means, a rotatable support shaft adjacent the otherend of said shaft, a gunsight shield mounted on said support shaft, agunsight fixed to said shaft and adjacent said shield, means forselectively locking together said shaft, shield and gunsight forterrestrial targets, and

means for selectively locking together said first housing and pivotplate for air targets.

References Cited by the Examiner UNITED STATES PATENTS 2,136,140 11/1938Langsner 89-41 2,390,516 12/ 1945 Crawford 81-41 2,696,144 12/1954Herlach 81-41 OTHER REFERENCES A.P.C. application of Haubroe, Serial No.313,395,

published May 4, 1943.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL BOYD, Examiner.

W. I. CURRAN, W. C. ROCH, Assistant Examiners.

1. A GUNSIGHT DRIVE LINKAGE COMPRISING, IN COMBINATION, ROTATABLE MEANSINCLUDING A GEAR SECTOR FOR ELEVATING A GUN ABOUT A FIRST CENTER OFROTATION, A PIVOT PLATE SPACE THEREFROM AND ADAPTED TO ROTATE ABOUT ASECOND CENTER OF ROTATION, A PAIR OF ARMS PIVOTALLY CONNECTING AT ENDSTHEREOF SAID ROTATABLE MEANS AND SAID PIVOT PLATE AT POINTS SPACEDRADIALLY FROM THE RESPECTIVE SAID FIRST AND SECOND CENTERS OF ROTATIONAND CONSTITUTING A PARALLELOGRAM LINKAGE PROVIDING CORRESPONDINGROTATION OF SAID ROTATABLE MEANS AND SAID PIVOT PLATE THROUGH SAID ARMS,A FIRST GEAR FIXED TO SAID PIVOT PLATE, A FIRST HOUSING ROTATABLYSUPPORTED ON SAID PIVOT PLATE, A RACK SLIDABLY SUPPORTED IN SAID FIRSTHOUSING IN ENGAGEMENT WITH SAID FIRST GEAR, A SECOND HOUSING HELD INCONNECTED SPACED RELATION TO SAID FIRST HOUSING BY A COMMON CONNECTINGMEMBER, A SHAFT ROTATABLY JOURNALED IN SAID SECOND HOUSING, A SECONDGEAR KEYED TO SAID SHAFT WITHIN SAID SECOND HOUSING AND IN ENGAGEMENTWITH SAID RACK, ROTATION OF SAID SHAFT THEREBY BEING RESPONSIVE TOROTATION OF SAID SECOND GEAR WHICH THROUGH SAID RACK, FIRST GEAR ANDARMS IS RESPONSIVE TO ROTATION OF SAID ROTATABLE MENAS, AND A GUNSIGHTFIXED TO SAID SHAFT AND THEREBY RESPONSIVE TO ELEVATION OF THE GUN.